I think it's just part of autocomplete, but it has to have an expanded set of contexts it uses. I think VSC only checks for actual existing types/properties in that context. But other editors can be more intelligent: IntelliJ's IDEs, for example, will automatically autocomplete a new method name to a method that some code is referring to but that doesn't exist yet (it knows I'm trying to create it). I'll check what variables you created and suggest some names for new variables depending on context. Etc.

It's really vague, but I'd still call it autocomplete.

Some editors, like Notepad++, end up using whatever they can find as a means to autocomplete. So you end up with a huge list of suggestions for anything you type. But it's because they lack the power to analyze the code and actually know what's allowed where you're typing.